1. Field of the Invention
The present invention is directed to an electromagnetic relay with a generally L-shaped armature, and more particularly, to a miniature electromagnetic relay with such armature rockable about an edge of a cooperating yoke.
2. Description of the Prior Art
There have been provided a number of electromagnetic relays having a generally L-shaped armature which is pivotable between an attracted position and a reset position in response to energization and deenergization of a cooperating coil for contact closing and opening. In the prior art relays of such construction as proposed, for example, in U.S. Pat. Nos. 4,303,742, 4,429,292, 4,340,876, 4,124,832, 4,101,856, and 3,474,367, a retainer spring means is required to constantly press the angled portion of the L-shaped armature against an edge of a complementary yoke so that the armature can pivot with its inside angle kept in exact coincidence with the yoke edge to effect a reliable contact switching operation.
Many of such retainer spring means are presented in a complicated construction which necessitates collaborate assembly into the relay structure. To overcome this inconvenience, it has been an industry demand to design the retainer spring means in a simple construction easy to assemble. Even with a simple retainer spring means, the addition of the retainer spring means becomes hindrance to the miniaturization of the relay where the number of the parts can be reduced to a minimum, although it is not serious in a relay of larger construction. Consequently, it has been a long-felt need in designing a miniature relay to eliminate the retainer spring means from the relay while assuring a stable armature operation of pivoting between two contact switching positions.